A clamp member and a counter pressure member are hingedly connected together about a rotary axis, and a fitting portion of a fitting protrusion that is positioned in a fitting recess is located at a foreside in an advancing direction of the pipe relative to a position where a bending operation of the pipe is initiated, and a mating portion at which a first groove part of the clamp member and a second groove part of a counter pressure member mate is located at a backside in the advancing direction of the pipe relative to the position where the bending operation of the pipe is initiated. The counter pressure member comprises a first member supported rotatably about the rotary axis, a second member detachably connected to the first member, and a third member detachably connected to the second member, which are connected together by a common connecting member (e.g., bolt).

Benders are disclosed relating to the convenient, accurate, and precise bending of tubing. Example benders include features such as a mandrel, adjustable mechanical stops, and scales having relatively high resolution along with significant distance from a central axis of the mandrel. Certain benders may include separate fine and coarse adjustments to bend angles and support mechanisms for controlling the bend plane angle.

A clamp member and a counter pressure member are hingedly connected together about a rotary axis, and a fitting portion of a fitting protrusion that is positioned in a fitting recess is located at a foreside in an advancing direction of the pipe relative to a position where a bending operation of the pipe is initiated, and a mating portion at which a first groove part of the clamp member and a second groove part of a counter pressure member mate is located at a backside in the advancing direction of the pipe relative to the position where the bending operation of the pipe is initiated. The counter pressure member comprises a first member supported rotatably about the rotary axis, a second member detachably connected to the first member, and a third member detachably connected to the second member, which are connected together by a common connecting member (e.g., bolt).

A pipe bend die unit comprises a clamp member having a first groove part of half-circular cross section on an outer peripheral surface thereof with a fitting recess extending in a peripheral direction by a first predetermined length on a planar surface perpendicular to a rotary axis, and a counter pressure member having a second groove part of half-circular cross section formed on an outer peripheral surface thereof, and a fitting protrusion extending in a peripheral direction by a second predetermined length from a tip end portion of the second groove part. The fitting protrusion is positioned in the fitting recess so that the first and second groove parts are combined to form a pipe-receiving groove of half-circular cross section. The counter pressure member and the clamp member are hingedly connected to one another so as to be rotatable relative to each other about the rotary axis.

Benders are disclosed relating to the convenient, accurate, and precise bending of tubing. Example benders include features such as a mandrel, adjustable mechanical stops, and scales having relatively high resolution along with significant distance from a central axis of the mandrel. Certain benders may include separate fine and coarse adjustments to bend angles and support mechanisms for controlling the bend plane angle.